C ++读取固定行数的整数行，每行中的整数数未知 [英] C++ Reading fixed number of lines of integers with unknown number of integers in each line

问题描述

我正在尝试读取数据并解决简单的问题，数据:

I'm trying to read in data and solve simple problem, data :

3               - number of lines to read in
1 1
2 2 2
3 4 

每行输入后，我想获得输入数字的总和，但是每行中整数的数量是未知的.使用完以上数据后，屏幕应如下所示:

after each line is entered I would like to obtain sum of entered numers, but number of integers in each line is unknown. After using above data screen should look like this :

3               
1 1
Sum: 2
2 2 2
Sum: 6
3 4 
Sum: 7

但是从我的算法中，我得到了输出:

But from my algorithm I've got the output :

3
1 1
Sum: 1
2 2 2
Sum: 4
3 4
Sum: 3

我已经编写了代码，但是不能正常工作(如上所述): EDITION
我改进了代码，并知道它可以在不使用字符串等的情况下正常运行，下面是正确的代码:

I've written code, but it doesn't work properly (as above): EDITION
I improved my code and know it works properly without strings etc., proper code is below :

#include<iostream>
using namespace std;
int main()
{
    int x;
    int t, sum;
    cin >> t;

    for(int i=0; i<t; i++) {
        sum=0;
        while(true)
        {
            cin >> x;
            sum = sum + x;  
            if(cin.peek()=='\n')
                break; //conditional break
        }
        cout << "Sum: " << sum << "\n";
    }
    return(0);
}

推荐答案

使用 getline 一次将一行读入 std :: string 类型的对象.然后使用该 std :: string 对象初始化一个 std :: istringstream 类型的对象，并使用提取器从流对象，直到失败.然后返回并阅读下一行.大概是:

Read a line at a time, using getline, into an object of type std::string. Then use that std::string object to initialize an object of type std::istringstream, and use an extractor to read int values from the stream object until it fails. Then go back and read the next line. Roughly:

std::string line;
while (std::getline(std::cin, line)) {
    std::istringstream in(line);
    int sum = 0;
    int value = 0;
    while (in >> value)
        sum += value;
    std::cout << sum << '\n';
}

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